Month

February 2022

West Coast Salmonids All Tired Out?

West Coast salmon and steelhead populations have declined steeply in the past century – a plight that biologists have primarily blamed on habitat loss. Dams, for instance, block adult fish’s access to historic spawning grounds, and juvenile survival is impacted by streamside development and water diversions. Now, it turns out, microplastic pollution may be a much bigger factor than anyone knew just several years ago. In 2019, scientists with the San Francisco Estuary Institute and the Los Angeles-based nonprofit 5 Gyres published findings indicating that car tire particles are one of the most prevalent forms of microplastic pollution flowing into San Francisco Bay. Then, in 2020, a team of West Coast scientists discovered that a chemical in these particles is...
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15
Feb

Eyeballing the Fish

Longfin smelt were what hooked Jim Ervin when he first learned about the UC Davis South Bay Fish Survey through a presentation at the 2012 Bay-Delta Science Conference. “They were catching them right there in our effluent channel!” recalls Ervin, a self-trained naturalist and former compliance manager for the San Jose-Santa Clara Regional Wastewater Facility. Intrigued, he contacted the researchers, rode with them on their next survey, and has been part of the project ever since, devoting more time to it after retiring from his wastewater facility job in 2018. “I have a free ticket to ride on the boat with fish experts who’ve been doing this for years,” he says. He began his Fish in the Bay blog in...
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Will Salmon Simmer Again?

After two critically dry years that coincided with Trump-era rollbacks to environmental protections, some iconic Delta fish are closer than ever to the point of no return. Last fall, for the second year in a row, the fall midwater trawl found zero wild Delta smelt, while a coalition of environmentalists and fishermen is asking a federal court to help prevent a repeat of 2021’s near-obliteration of endangered winter-run Chinook salmon. Their lawsuit is just one of the balls to watch this spring as several projects and processes that could radically affect how much water flows through the Delta, and when, percolate. “There’s a lot going on right now, kind of bubbling just below the surface,” says the Natural Resource Defense...
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15
Feb

Gone Fishing

As the weekend dawns and California slumbers, the sportfishers descend, like clockwork, on the banks and waves of the San Francisco Bay and Sacramento-San Joaquin Delta. They carry nets for herring or poles for sturgeon, heavy and light tackle, bloodworms or anchovy or any number of delectable morsels to attract the desired target. They tread industrialized East Bay shorelines and marshy Delta banks, hop aboard sporty six-pack boats for more ambitious trips or humbler craft for a leisurely solo excursion. They catch (and often release) a smorgasbord of species: halibut, kingfish (white croaker), or sturgeon around the Bay, or striped bass, salmon, and black bass in the many tendrils of the Delta. “Here, you get both worlds, fresh and salt,”...
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15
Feb

South Bay Trawls Show Fish Like Restored Shores

Twelve years ago, scientists at UC Davis began a survey of the southern end of San Francisco Bay — the Lower South Bay — to see how fish responded to the South Bay Salt Ponds Restoration Project. They discovered an unexpectedly diverse and robust aquatic community and a previously unknown spawning ground for the longfin smelt (Spirinchus thaleichthys), listed as endangered in California and a candidate for federal protection because of its declining numbers. The team, led first by Jim Hobbs and now by Levi Lewis, has complied an invaluable long-term dataset and enhanced our understanding of the surprising ecosystems of the bottom of the Bay. In addition to journal publications, their findings have been shared in blog posts by...
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15
Feb

Big Boulders, Big Benefits to Coyote Creek Fish

As a source of flowing water, upper Coyote Creek is unreliable at best. Though storms swell its banks in winter, Mediterranean-climate summers shrink this South Bay stream to a series of isolated pools by August. “By October right before the rains come, we’re down to these really small pools that have all the fish in them,” says retired U.S. Environmental Protection Agency ecologist Rob Leidy. Leidy and UC Berkeley fish ecologist Stephanie Carlson began monitoring the annual dry-down of upper Coyote Creek in 2014, with the help of Hana Moidu and other graduate students. The creek itself originates in Henry W. Coe State Park and flows to the Bay through Coyote and Anderson lakes south of San Jose. The scientists...
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15
Feb

Murky Future for Herring

This winter, herring spawns in San Francisco Bay – visible from land as frenzies of birds and pinnipeds and even water discolored by herring milt – have been few and far between, according to recreational fishers who pursue the fish each year using hand-thrown cast nets. With few other eyes on the resource, it seems reasonable to assume that the downward trend in biomass documented through the 2019-2020 winter has continued. But nobody knows for sure. For decades, the California Department of Fish and Wildlife has carefully monitored and assessed the Bay’s herring runs. The research used a variety of surveys to produce annual biomass tonnage estimates almost every year since the 1970s. But in recent years a new herring...
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15
Feb

Natives Who Can Rough It

Name a native fish. One that spends lots of time in the Delta. One that’s not a salmon, smelt, or sturgeon. One whose population isn’t plummeting, and in fact seems to be doing just fine. By now the list of possibilities has been shortened severely — though not exhausted. A number of native fish still ply Delta waters in stable numbers, but precisely because there are no restoration projects, monitoring programs, or conservation efforts designed to save them — or perhaps because they’re not game fish, or particularly large, or traditionally “charismatic” —  theirs are not household names. To the extent that they are recognized by the general public at all, some are even referred to, somewhat derisively, as “rough”...
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15
Feb

Let’s Not Forget Suisun Marsh

I started sampling the fishes of Suisun Marsh in 1979 because one of my UC Davis graduate students was looking for a place to study tule perch, a live-bearing native fish. We found not only a lot of tule perch in the marsh, but also an abundance of other native fishes. Clearly, this was a good place to study species for which we had little information at that time. Two things helped with our new project. First, sampling boats could be launched less than an hour’s drive from campus. Second, the California Department of Water Resources needed a study to examine effects of new tidal gates on fish. The gates are designed to retain fresher water in the marsh to...
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Hatchery Delta Smelt Released to Wild

On a mild day between rainstorms in mid-December, wildlife biologists outfitted in rubber boots and orange lifejackets load drum after drum of precious cargo onto a small boat docked in Rio Vista, a town on the Sacramento River in the Sacramento-San Joaquin Delta. There is little fanfare but the occasion is nonetheless momentous. The shiny silver drums contain thousands of Delta smelt — finger-size imperiled fish unique to the Delta — that were raised in a conservation hatchery. Today marks the inaugural release of captive smelt into the cold, murky waters of their native home. “For the first time, we’re seeing if it’s possible for hatchery-raised Delta smelt to be released into the wild, survive, and successfully reproduce,” says Katherine...
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15
Feb

Sturdy Sturgeon

A 90-year-old Australian lungfish at San Francisco’s Academy of Sciences has received a lot of press lately, but there is a wild fish species living in the San Francisco Bay that has the potential to live that long or longer — or so we think. While one white sturgeon caught in the Columbia River Basin was estimated to be 104 years old, the life expectancy of white sturgeon, Acipenser transmontanus, which includes the Central Valley population endemic to the San Francisco Bay, is hard to pin down. “There are old ones out there, but it’s really hard to give a number because we just don’t have it,” says John Kelly, statewide sturgeon coordinator for the California Department of Fish and...
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15
Feb

The Complexities of Monitoring Steelhead

For more than two decades, steelhead — listed as federally threatened in 1997 — have been monitored throughout the state. However, until recently that monitoring has been a haphazard affair. Each local jurisdiction has established a different system, using different methods with different degrees of intensity, according to a 2018 study examining monitoring within the Central Valley and its environs. In some areas, primarily the Sacramento River watershed, which drains the vast northern part of the valley, data has been collected more comprehensively. In other areas, such as the San Joaquin River system to the south, more gaps remain. And in general, monitoring tended to focus solely on migrating numbers and not more detailed life history demographics. “We need to...
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15
Feb

Better Living Through Fish – Editor’s Desk

I come from a long line of fisherfolk. My grandparents had a tiny cabin on a Quebec lake. We visited some summers. My grandfather let me drive the big white speedboat at a snail’s pace while he smoked cigars and trolled for trout off the stern. Once, when I caught one bigger than his catch-of-the-day, he “accidentally” knocked it back into the lake with the net. On the dock, we’d sunbathe while he cast lines overhead with a precision worthy of the movie A River Runs Through It. At the lake, we ate trout and eggs, trout salad, baked trout. I survived on spoonfuls of Cool Whip. (Photo above is editor as a teenager with Kay Rubbra, my grandmother, and...
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